O Gauge Trains and O Scale

The proper definitions of O scale and O gauge are sometimes confused so let’s get this sorted out at the beginning:

Scale refers to the proportions of the modelled superstructure, relative to the prototype, ie., to the actual full size loco, building, etc. being represented

Gauge defines the actual track width of the model. Most commercially produced model track is a compromise between appearance and offering a satisfactory, trouble free, running surface.

O SCALE Railways

In the UK O Scale is commonly 1/43.5 or 7mm to the foot.

In Europe O Scale is 1/45.

In the USA O Scale is 1/48.

Each region tends to design models to its own scale.

O Gauge Trains

Great Britain’s inventors such as Cornishman Richard Trevithick produced the first steam locomotives, and UK engineers designed engines and rolling stock based on a track width of 4′ 8.5″, a width that was found to give good performance and capacity, with stability, security and passenger comfort. Isambard Kingdom Brunel used a wider gauge giving greater comfort , but unfortunately the Great Western Railway found itself in a minority and ended up tearing up their superior track to match everybody else.  In the 19th Century, British heavy engineering dominated early railway rolling stock production, exporting their products every where, and 4′ 8.5″ became the Standard Gauge of the World.

All model railway track thus has a basis deriving from a Standard Gauge Track width of 4′ 8.5″.

All regional model manufacturers design their O Scale rolling stock, with minor regional scale differences; unfortunately manufacturers support their rolling stock with track made to the same regional scales, so there is NO Universal O gauge track width!

Wide or Narrow Gauge Track

Differences in regional “Scales” give different prototype gauges to these different model track widths. For example, using specially manufactured 16.5mm narrow gauge track, built at 7mm to the foot: 

1. UK O Scale rolling stock [1/43], becomes a Narrow Gauge Track of 2′ 4″, and is referred to as ‘On16.5′ [less fussy modellers portray gauges between 2' and 3'!].

2. European O Scale rolling stock [1/45], becomes a narrow gauge Track of 2′ 5.5″, and is referred to as ‘Oe’ portraying a 750mm prototype.

3. US O scale rolling stock [1/48], becomes a narrow gauge track of 2′ 6″, and is referred to as On2 1/2 [or On30 as in 30"].

Die-cast metal models compatible with O Gauge

Many manufacturers produce die-cast models of trucks, cars, buses, construction equipment and other vehicles in scales compatible with or similar to 0 scale model trains. These are available in 1:43 scale, 1:48 scale and 1:50 scale. Manufacturers include Conrad, NZG, Corgi, TWH Collectibles and many others. These are popular with collectors and easy to find.

Corgi’s Bassett Lowke O gauge trains were re-launched in 2007 with a new range of detailed locos, goods wagons and accessories.

In the United Kingdom, O gauge trains equipment are produced at a scale of 1:43, which is 7 mm to the foot (using the common British practice of modelling in metric prototypes originally produced using Imperial measurements). It’s often called 7 mm scale for this reason.

Although toy trains were historically produced to this scale, O gauge’s popularity across the whole of Europe reduced after World War II, and the standard is rarer than in the United States. Modelling in O gauge in fact almost died out in Britain but enjoyed a resurgence in the 1990s as modellers developed a new appreciation for the level of accurate detailing possible in this scale. Few ready to run models are produced in this scale; most are available only as kits for assembly by the modeller or a professional model-builder. O gauge is considered an expensive scale to model in, although the necessarily smaller scope of a larger-scaled layout mitigates this to some extent. The two dominant British manufacturers, Bassett-Lowke and Hornby, ceased production of O gauge trains in 1965 and 1969, respectively. However, Ace Trains and a revived Bassett-Lowke are once again producing tinplate O gauge sets, many of them reproductions of classic Hornby and Bassett-Lowke designs, and Heljan has also recently joined the market producing O gauge diesel locomotives.

A true-to-prototype version of British 7mm O gauge exists, called ScaleSeven (S7) which uses 33 mm gauge to represent British standard gauge in a scale of 1:43.5.

The British 1:43 rail scale gave birth to series of die cast cars and model commercial vehicles of the same scale which gradually grew in popularity and spread to France, the rest of Europe and North America at the same time that the rail models were becoming less popular.

7mm scale is also popular for modelling narrow gauge railways, a section of the hobby supported by the 7mm Narrow Gauge Association.